After some unstructured research I found that within the lxc container of Alien Dalvik there’s a directory /data/app which contains some APK data. Most of the directories can directly be mapped to an installed app. However there was a directory called vmdl2083684193.tmp with an empty file with the name of the latest apk package that failed to install. So I deleted that directory and managed to install the app and others as well.
That directory is also available on the Sailfish side at /home/.android/data/app
Hence, if you run into the same problem, make sure there are no stale directores in the form /home/.android/data/app/vmdl??????????.tmp.
Hope that helps someone eventually